i know this rellay isn't techincal but on my 1985 500sel there is a button on the ftont passenger seat. it is loacated on the back about half way up to the left it is under the leather but you can see it sticking up. what is it for.

------------------
--------------------
1985 euro 500sel 220k
1981 300sd 278k sold
1989 chrysler 2.2l Turbo
Leabaron 130k
1990 320sl (hopefully)